To advance a hull by horizontally moving a fin erected in the vertical direction.
Two horizontal moving rods 44 are horizontally movable by taking fulcrum axes 45 as fulcrums, and they are always pulled inward by a spring 46. Fins 50 are attached to the tips of stern sides of the horizontal moving rods 44 so as to be moved with the movement of the horizontal rods 44 and so as to be freely and horizontally turned at specified angles. On the front ends on the bow sides of the horizontal rods 44, ropes 55 are connected to a pedal 58 through pulleys. When the pedal 58 is pushed forward by an occupant, the ropes are pulled, two horizontal moving rods 44 are moved so as to be extended to the stern side, and the fins are also moved. In this process, reaction from the water acts as propulsion force of the hull 41. When force of a leg is relaxed, the pedal 58 is drawn back, the horizontal moving rods 44 on the stern side are closed, and propulsion force is generated.
SHIMIZU HIDEO
KAMATA KENSAKU
YOSHINAGA MAKOTO
